CVE-2026-42477

A heap-based out-of-bounds read vulnerability in RWObj_Reader::read in the OBJ file parser in Open CASCADE Technology (OCCT) V8_0_0_rc5 allows user-assisted attackers to cause a denial of service or obtain sensitive information by persuading a victim to open a crafted OBJ file. The issue occurs because Standard_ReadLineBuffer::ReadLine() can return a 1-byte buffer for a minimal OBJ line, and RWObj_Reader::read() calls pushIndices(aLine + 2) without validating the buffer length.

Published: 2026-05-01 Last update: 2026-05-10 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2026-42477 is rated Low Risk (29/100): CVSS High severity, with low exploitation likelihood (EPSS 0.01%). Monitor for updates and reassess as exploit intelligence or EPSS changes.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2026-42477

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-05-02 — 0.01% —

Full EPSS history (1 record total)

Common vulnerability scoring system (CVSS) metrics for CVE-2026-42477

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
7.1 3.1 HIGH
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:H Click to expand
Attack vector (AV:L)
They already need access on the box, or another person has to do something wrong; it’s not a remote drive-by.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:R)
A real person has to do something—click, install, enable—otherwise it doesn’t land.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 1.8 5.2 [email protected]
5.5 3.1 MEDIUM
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H Click to expand
Attack vector (AV:L)
They already need access on the box, or another person has to do something wrong; it’s not a remote drive-by.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:L)
A normal user session is enough; they don’t have to be admin.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 1.8 3.6 134c704f-9b21-4f2e-91b3-4a467353bcc0

Weakness enumeration for CVE-2026-42477

GitHub Security Advisory for CVE-2026-42477

GHSA-3vcm-9wgv-947g · Severity: high — A heap-based out-of-bounds read vulnerability in RWObj_Reader::read in the OBJ file parser in...

OS Trackers for CVE-2026-42477

vendor priority summary link
debian not yet assigned CVE-2026-42477 not yet assigned priority: Debian including 1 source packages (opencascade), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): open 5. https://security-tracker.debian.org/tracker/CVE-2026-42477
ubuntu medium CVE-2026-42477 medium priority: Ubuntu including 1 source packages (opencascade), 6 status rows across 6 suites (focal, jammy, noble, questing, resolute, upstream): needs-triage 6. https://ubuntu.com/security/CVE-2026-42477

Affected software / configurations for CVE-2026-42477

Vendor Product Version Raw CPE
opencascade open_cascade_technology <= 7.9.3 cpe:2.3:a:opencascade:open_cascade_technology:*:*:*:*:*:*:*:*
opencascade open_cascade_technology 8.0.0 cpe:2.3:a:opencascade:open_cascade_technology:8.0.0:beta1:*:*:*:*:*:*
opencascade open_cascade_technology 8.0.0 cpe:2.3:a:opencascade:open_cascade_technology:8.0.0:rc1:*:*:*:*:*:*
opencascade open_cascade_technology 8.0.0 cpe:2.3:a:opencascade:open_cascade_technology:8.0.0:rc2:*:*:*:*:*:*
opencascade open_cascade_technology 8.0.0 cpe:2.3:a:opencascade:open_cascade_technology:8.0.0:rc3:*:*:*:*:*:*
opencascade open_cascade_technology 8.0.0 cpe:2.3:a:opencascade:open_cascade_technology:8.0.0:rc4:*:*:*:*:*:*
opencascade open_cascade_technology 8.0.0 cpe:2.3:a:opencascade:open_cascade_technology:8.0.0:rc5:*:*:*:*:*:*

References for CVE-2026-42477

cvelogic Threat Intelligence